Because of their utility and versatility, fiberscopes are employed in extremely diverse applications: from nuclear reactor inspection to medical diagnosis. The ability to image an object that would normally be impossible to access without extremely invasive methods is indispensable in many fields.
In general terms, a fiberscope employs a flexible bundle of glass fibers to transmit an image from the distal end of the fibers, which can be positioned adjacent to the object to be imaged, to the proximal end of the fibers which can be positioned in a more accessible location. The bundle of fibers used for imaging can be referred to as an imaging fiber bundle. Current technology makes it possible to construct a sub-mm diameter imaging fiber that incorporates thousands of individual fibers. For instance, an imaging fiber bundle having 10,000 individual fibers that each have a 5 um diameter can have an outer diameter of only 0.5 mm. During imaging, each fiber serves as a pixel for the image and transmits this pixel via internal reflection from the distal end of the fiber to the proximal end of the fiber. The individual fiber size determines the pixel size for the transmitted image, and the size and density of the fibers influence the bending flexibility of the imaging fiber bundle.
Since the distal ends of the fibers in the imaging fiber bundle cannot image the object, fiberscopes require a distal imaging lens to image the object onto the surfaces of the distal ends of the fibers. The surfaces of the distal ends of the fibers can also be referred to as the distal end face of the imaging fiber bundle. In addition, since the proximal end of the imaging fiber bundle is very small, a viewing device is used to magnify the image that has been transmitted along the image fiber to the proximal end of the imaging fiber bundle so that the image can be viewed. The viewing device can utilize a lens arrangement and/or electronic sensor to magnify the image for viewing.
Effective utilization of the fiberscope generally requires illumination because fiberscopes are commonly employed to interrogate cavities which have little or no light. In conventional fiberscopes, this illumination is commonly provided by a series of physically distinct fibers that are dispersed around the circumference of the image fiber and are connected to a light source. In contrast to the imaging fiber, these illumination fibers are generally fewer in number and much larger in diameter than the imaging fibers. These illumination fibers are physically distinct from one another and from the imaging fibers. Further, the illumination fibers are separated from the imaging fibers using an opaque material such as a plastic jacket and, typically, the illumination fibers can each include a cladding and/or jacket.
Some fiberscopes can also be used for performing tasks at the distal end of the scope. These fiberscopes can include an integral tool that is incorporated into the distal end of the scope for performing a specific task. Other types of such fiberscopes can include one or more working channels into which different types of tools can be inserted and guided to the distal end of the scope for performing a variety of different tasks. Fiberscopes having one or more working channels can provide more flexibility for performing tasks as compared to fiberscopes with integrated tools.
A common challenge in fiberscope construction and, in particular, medical endoscopes, is seen with respect to economical construction and utilization. For instance, a medical endoscope having features as described could cost thousands of dollars. Disposal of such a device after a single use is prohibitively expensive. Therefore, the used endoscope is typically returned to the manufacturer for sterilization. Such a service, particularly for what is considered a bio-hazard, can be expensive. Accordingly, it is desirable to decrease the cost of a fiberscope while maintaining the quality and versatility of the device.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon reading of the specification and a study of the drawings.